Adaptive rowing? Sure. Cross-country skiing? Why not? Hand-cycling? She dominates. But the 19-time Paralympic Games medalist’s most meaningful achievements might come as a mentor.

A Japanese utility has started dismantling an old nuclear reactor with an eye toward building a new one, a spokesman said Tuesday, as the country drives for more clean energy.

From exploring the vast and unknown corners of space to pushing the laws of nature to their breaking point, sci-fi is a genre ...